1. Field of the Invention
The present invention relates to a vehicle abnormality detecting device for detecting whether or not an installation position and an operational state or the like are appropriate with respect to functional parts such as various kinds of sensors installed in a vehicle.
2. Description of the Related Art
In recent years, many functional parts such as various kinds of sensors to exhibit a predetermined effect are mounted onto a vehicle in order to facilitate higher functionality and higher safety. For example, Japanese Unexamined Patent Publication No. H06-138232 indicates that a radar head unit of a radar device is arranged in an engine room adjacent to a front grill of the engine room in order to prevent collisions by detecting obstacles such as a preceding vehicle.
The above radar head unit is arranged in the engine room so as to prevent damages easily made by a contact with other vehicles and obstacles.
However, in the case of arranging functional parts such as the above radar device in a portion such as a bumper which is easily influenced by a contact with other vehicles and obstacles, there was a danger of resulting in inability to exhibit functions thereof appropriately due to deformation of an installation portion caused by the shock.
It is therefore considered to arrange a state detecting unit composed of a sensor and a switch or the like for detecting an installation position and an operational state of functional parts such as the radar device, including an abnormality detecting unit for detecting the abnormality on the basis of a state of current supply to the state detecting unit, in order to detect whether or not the functional parts is in a state of being capable of exhibiting its functions appropriately.
For example, if deformation of an installation portion caused by a shock due to a contact with other vehicles and obstacles is detected by the abnormality detecting unit, a warning display or the like is exhibited for a driver so that maintenance can be facilitated.
If a switch mechanism of a mechanical contact system such as, for example, a momentary switch is employed as the state detecting unit for detecting an installation position or the like of the functional parts as described above, it is necessary to supply a relatively large detection current to the switch in order to avoid a conduction failure generated by having an oxide film on a contact surface thereof due to a secular change. Meanwhile, even if other switches and sensors are employed as the state detecting unit, it is necessary to supply electrical power for detecting a state.
However, if a conduction state of the switches and an active state of the sensors are continued from one cause or another, or if an On state of the switches is maintained and a short-circuit failure is generated due to mechanical deformation of the installation portion for example, power is constantly consumed, having a problem such as inability to operate an engine due to battery consumption especially when such a state is maintained for a long period of time during a state that an ignition key is turned off.